Specifications

MBX Bridge Help
Cyberlogic Technologies Inc. - 14 -
Source Device
Type Routing
Destination Device
Type Routing Resulting Address
MB+
1.2.3.4.5
MB+
3.2.0.0.0
3.2.0.0.0
MB+
7.2.15.13.0
E
IP = 192.168.4.MB3 DI = MB4
192.168.4.15 DI = 13
MB+
6.8.22.0.0
MB
MB3-10
12
MB
9
MB+
2.MB.0.0.0
2.9.0.0.0
MB
11
E
IP = 192.168.43.MB DI = 0
192.168.43.11 DI = 0
E
10.67.7.1 DI = 5
MB
DI+32
37
E
52.202.3.18 DI = 6
MB+
IP4.DI.IP1+IP3.26.0
18.6.55.26.0
This table shows examples of some Destination Routings and how they would route
typical messages. In each case, device type E refers to an Ethernet device, MB to a
Modbus device and MB+ to a Modbus Plus device.
Master Path Resource Management
The MBX Bridge uses data master and program master paths to route messages to their
destinations. Some MBX devices have only a limited number of these paths available, and
once these resources are exhausted, no additional communication over that device is
possible. The MBX Bridge operates concurrently with other applications communicating
over the same MBX devices, so it is possible for the bridge to interfere with their
communication. To minimize this, the MBX Bridge intelligently manages its master path
use. It does this by allowing the user to limit the number of master paths that the bridge
may use for each destination device.
For example, the PCI-85 allows a maximum of eight program master paths for all
communications. If the user specifies that the bridge may use only two of these paths,
then at least six will remain available for other applications.
Some device types, such as Ethernet MBX, can support an unlimited number of paths.
Therefore, the user can elect to impose no limits on path usage on these types of
devices.
Note
Although the physical Modbus Plus adapter cards allow a maximum of eight data
master paths, the MBX Driver removes this restriction. It allows up to 65,535 logical
data master paths to share the eight physical data master paths on the adapter card.
(Program master paths are still limited to a maximum of eight, however.)
This technique is highly efficient and therefore most users should configure the MBX
Bridge to use an unlimited number of data master paths. Users who are concerned
with the amount of memory used by the bridge, or want to limit the loading on the
network, may still wish to limit the maximum number of data master paths used.